KEY POINTS:
How do you avoid buying a leaky house?
Out of the country's 1.4 million housing stock, only a portion are not weathertight or prone to spring leaks over time.
The Department of Building and Housing's website (www.dbh.govt.nz) provides a guide to spotting a potential lemon under its weathertight
links.
It firstly warns against Mediterranean-style houses with monolithic cladding although the Leaky Homes Action Group challenges this, saying houses with other cladding types leak.
"Every house will leak some time in its life, regardless of design or cladding," says the group's chief, John Gray, who warns to get a good pre-inspection report before buying.
The department website says monolithic cladding houses usually have textured wall surfaces made out of plaster over polystyrene or fibre cement sheet. The site warns against wall claddings in contact with the ground, roofs with narrow or no eaves, and houses more than one storey high.
Design features such as solid balustrades, complex roof design and envelope shapes where roofs frequently intersect walls on upper floors should also ring warning bells.
The website warns against those houses built from the 1990s, decks and balconies that jut out from walls, enclosed or concealed gutters and inadequate sub-floor ventilation for timber floors.
Mr Gray said houses with balconies integrated into the roof and with rooms below were particularly susceptible.
The government website says many Mediterranean-style house were built with untreated, kiln-dried framing timber which is susceptible to rot if it gets wet and cannot dry out.
"There is little comfort to be gained by having treated timber either as although it is not susceptible to the early onset of decay as experienced with kiln-dried untreated timber, expert opinion indicates that even treated timber will fail if there is continual moisture ingress and the treatment is leached out," Mr Gray said.
The department's website says if you are interested in a home with these types of features, get an independent building survey.
"Ask your building surveyor to look particularly for signs of water damage or potential leaks. They should use a moisture meter.
"However, not all defects can be found, so ask the person doing the inspection to highlight the areas they couldn't check and identify risk areas."
